Groundwater Nitrate

Groundwater is the main source of drinking water for many small agricultural communities. Nitrate
concentration in groundwater is a major problem in Nira River basin area, which is mainly due to the
run off or seepage of chemical fertilizers from the agricultural field. A total of 45 water samples were
collected in the period of post-monsoon (POM) winter and pre-monsoon (PRM) summer seasons from
bore wells. The water samples were analysed using standard methods of APHA suggested for
analysis of nitrate. Groundwater quality parameter varies spatially in different seasons. In the present
study, spatio-temporal variation in nitrate levels in bore wells of Baramati Tahsil area is examined.
The results of analysis showed that nitrate concentration in POM and PRM was above the maximum
permissible limit of WHO and BIS recommended for drinking purpose. In POM 74% groundwater
samples from canal irrigated area and 11% from non-canal-irrigated area were above the standard
limit of WHO and BIS. In PRM 66.67% and 11% samples respectively from canal irrigated and noncanal-
irrigated area were above the maximum permissible limit of WHO and BIS (45 mg/l). This
indicates that peoples especially children using the water from bore wells with higher concentration of
nitrate than standard limit, stands a high risk of methemoglobinemia (sometimes referred to as “Blue
baby syndrome”). In canal irrigated area concentration of nitrate was found higher than the non-canalirrigated
area. This may due to the use of more nitrogenous fertilizers by farmers in their farms,
improper disposal of animal and human wastes in canal irrigated area as compared with non-canalirrigated
area. The groundwater of such bore wells was not suitable for drinking purpose without
treatment at the time of analysis. Nitrate containing groundwater is more effective and useful for
irrigation purpose. The nitrogen can be removed from drinking water by using treatment such as ion
exchange, biological de-nitrification and reverse osmosis.